| abstract |
(57) [Summary] (Modified) The present invention relates to a novel pyridonecarboxylic acid derivative or a salt thereof. [Structure] General formula [I] "In the formula, R 1 represents an amidino group which may be protected; R 2 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an alkylamino group, an optionally protected hydroxyl or amino group; R 3 is a hydrogen atom or a carboxyl protecting group; R 4 is substituted Optionally an alkyl, alkenyl, cycloalkyl, aryl or heterocyclic group; Y is an optionally substituted lower alkylene group; A and B are N, CH and the like. ] The pyridone carboxylic acid derivative represented by these, or its salt. [Effect] The pyridonecarboxylic acid derivative of the general formula [1] or a salt thereof has an inhibitory action on platelet aggregation and is useful as a preventive and therapeutic agent for diseases associated with platelet aggregation. |